Here's a comicvine page that shows most of the covers in order, although it has no information on the contents.
https://comicvine.gamespot.com/book-and-record-set/4050-38705/I thought for many years that these were all done by Continuity Associates, but it turns out, only in the 1975-1978 period, and maybe a later return to Continuity with the Buckler stories toward the end.
But they began as Marvel reprints (10-17).
Then Planet of the Apes adaptations (18-21).
Then the ones produced by Continuity (24-35), then switched to a series of Classics Illustrated type adaptations (37-42, and 47). With a few STAR TREK stories tossed in at the end (45-46).
They appear to have made a variety of attempts to reach an audience already reading comics, with an initial offering of Marvel reprints, and several other pushes with the PLANET OF THE APES adaptations, SPACE 1999, STAR TREK after, aiming at different trends in popular culture.
